To be eligible, guilds must have at least 20 members able to participate in two hours of raiding two nights per week; they must also currently be at 11/11 in Hammerknell. Candidates are also expected to have mature members capable of responsible feedback, since they are going to be testing new and possibly buggy combat. If you think your guild qualifies, have your guild leader (which may be you) respond to the call. And be prepared to blow through everything in minutes once it goes live -- that's always the risk.